Stitching Holes and Pricking Irons

Pricking irons

A pricking iron is described by its blade shape, pitch (the spacing between holes), blade width and length, blade angle, and the blade counts it comes in (for example 1, 2, 5 and 9 prongs).

The Pricking irons section of the side panel lists your irons. Click an iron to choose it, and a blade count under it for manual pricking. Built-in irons include diamond, French, flat and round irons from 3 mm to 5 mm, and 1/8″ and 5/32″.

Blade shapes: Diamond (slanted diamond), French (thin slanted slit), Flat (straight slit), Round (round hole). A blade width of 0 makes each hole a single line, useful for cutting machines.

The Pricking irons dialog (Ctrl+H)

Stitch ▸ Pricking irons… (Control+H on a Mac too) manages your irons:

The list: add (+, copying the selected iron), delete (not the built-in ones), move up and down.
Fields: Name, Kind (blade shape), Pitch, Width and Height (or Diameter for round irons), Blade angle, Blades (the counts, for example 1, 2, 5, 9).
A preview of one press, with Reverse blade and Show axis.
Import… / Export… irons as a .pcadirons file.
Apply to selected holes changes the selected holes to this iron's shape.
Apply changes keeps your edits; Cancel drops them.

The Stitching tool (P)

Choose an iron first ("Choose a pricking iron in the side panel first.").

Auto mode

Click the stitch line where pricking should start.
Move to where it should end. The route the holes will follow lights up, and the preview shows the holes and the resulting pitch ("24 holes, auto pitch 3.9130 mm. Click to prick.").
Click to prick. To prick a whole closed loop, click the start point again, or double-click the stitch line where pricking should start. A single click always starts an open run, so you can prick part of a loop.

The status bar gives the number of holes and the pitch (of the longest side, when corners split the run): with Auto pitch it is the "Auto pitch" found for the run; with Fixed pitch it also gives the estimated best pitch, the pitch nearest yours that would fit the run exactly ("Pricked 19 holes, pitch 4.0000 mm. Estimated best pitch: 3.9474 mm."); Auto pitch would use it.

The route follows connected lines of the same line type, so you can prick along a whole outline made of lines, arcs and curves. Holes that are already there are kept as fixed points: prick part of a line by hand, then the rest automatically. Click an existing hole to start (or end) the run exactly in it: the hole is kept and the new holes link on from it.

Two edges that will be sewn together need holes that line up. Use Fixed pitch and start both from matching points (the same corner, say); the holes then match hole for hole, and any length left at the end stays without a hole. When the edges differ in length and every hole needs a partner, use Number of holes with the same number on both, or prick one edge and copy its holes to the other with Stitch ▸ Project stitching holes on the selected lines.

Auto options:

Option	Effect
Spacing	Fixed pitch (the default): exactly the pitch you enter, the iron's own by default. The run stops at the last whole pitch before the end you click, so no hole is ever squeezed in there. Before a corner, or where a loop closes, a hole goes right on the corner and the odd bit of length is shared over the last few gaps, none more than 10% off the pitch when the side is long enough. Auto pitch: the pitch closest to the iron's that fits the section exactly, so there's a hole right at each end, but two lines of different lengths get slightly different spacing. Number of holes: exactly N holes.
Fixed pitch / Number of holes	For those modes.
Corners	Hole on every corner: a hole exactly on each corner, each side pitched separately. All junctions: a hole at every joint between shapes. Uniform: no corner holes, the pitch runs straight through.
Corner angle	With Hole on every corner: joints sharper than this angle (default 160°) count as corners. A small bevelled corner (an arc) gets its hole at the arc's middle.
Reverse	Holes as made with the iron turned round.

Manual mode

Like pressing a real iron. The tool always opens in Auto mode; Manual lasts until you close the app.

Choose a blade count under the iron (for example 2).
Click the stitch line: that many holes are placed along it from the click. Click an existing hole to put the iron's first blade in it.
Click again further along: the next press reuses the last hole, as a real iron does. Ctrl+Z takes back the last press, and the next one starts again from the press before it (or from your first click when none is left).
One prong fewer places one hole fewer on the next press, so the run ends where you want (it clears itself after that press). It is greyed out when that press would add no hole: with a 1-blade iron, or a 2-blade iron going on from the last hole.
Esc ends the session.

Both modes: Show stitches turns on the stitch preview; Even and Odd show the front and back stitches.

Stitching order

Holes are linked in the order the thread goes through them. Pricking links them automatically.

Right-click a hole:

Choose the next hole: then click the hole that should come next (Esc cancels).
End the stitching here: the run stops at this hole.
Fix stitching order from here: relinks the holes along their stitch line, starting at this hole.
Always show the stitch preview: the stitches of this hole's run (of every selected hole's run) are drawn as thread even while the stitch preview (F6) is off. Don't always show the stitch preview turns it off again.

Choose the next hole and End the stitching here turn a hole round when its new links make it face against the way the thread goes through it, as Fix stitching order does; holes whose links don't change are left as they are. Ctrl+Z undoes the links and the turn together.

Stitch ▸ Fix stitching order relinks all the holes on the selected lines. When the order turns round, each hole is turned to face the new direction (it looks the same, but the stitch preview's thread now leaves it towards the next hole). On a closed outline stitched only part of the way round (a pocket left open along one side, say), the run stays open at the gap instead of closing across it.

Automatic checks. Pasting, flipping (Ctrl+I / Ctrl+J), Symmetry (Ctrl+L) and opening a project check the stitching order of the holes involved and repair only what is broken, as part of the same step:

a stitch line whose holes have a link that is only half there (one hole names the next, but that hole names no previous one; files written by other programs often look like this) is relinked along the line, keeping the direction most of its links take;
a hole facing against the way the thread goes through it is turned round.

Stitch lines without a broken link keep your own orders, jumps between lines and branches as they are. Deleting holes clears the links to them.

Command	Key	What it does
Pricking irons…	Ctrl+H	See above.
Delete holes on the selected lines	Ctrl+Del	Removes the holes on the selected lines; the lines stay.
Fix stitching order	–	See above.
Count holes	–	Counts the holes on the selected lines.
Reverse holes	–	Turns the selected holes as if pricked with the iron reversed.
Change hole shape…	–	Opens the Pricking irons dialog to apply another iron to the selected holes.
Project stitching holes on the selected lines	–	See box stitch below.
Straighten curves into strips…	–	See box stitch below.
Thread catalogue…	–	See Threads.

Box stitch and gussets

For sewing a gusset (a strip) to a curved panel, the holes on both must match.

Project stitching holes on the selected lines: select a pricked curve and the line(s) it will be sewn to. Each hole is recreated on the target at the same distance along it, measured from the target's end nearer the start of the pricked curve, and linked in order along the target. The target is looked for within Box stitch: how far to look for the matching line (Options, default 100 mm).

Straighten curves into strips…: turns each selected pricked curve into a straight strip of the same length, with its holes, placed below the selection. The Allow for leather stretch dialog offers:

No allowance;
Set the strip's length (all positions scaled to that length);
Stretch by a percentage (for example −1.5 % for thick leather bent round a tight curve).

Chains: selected lines joined end to end act as one line in both commands, measured along the whole chain: select every piece of a curved panel edge (for example two arcs and a straight line) and the gusset edge, and the holes follow round the corners. Pricked lines only join pricked lines and bare lines only bare ones, so a pricked edge and the bare edge it meets at a corner stay apart. A line joined to no other selected line works on its own.

Stitching holes and pricking irons